Why does the black widow kill her mate?

Answers

Female black widows do not actually habitually kill their mates. It’s a noted mating behavior, but it is generally “the exception more than the rule”.

When females do kill the male post-mating, it’s generally more as a feeding impulse than anything else. Females don’t need males post-mating (all subsequent fertilization can be done with the already absorbed genetic material), so if a female is in need of a quick meal post-mate, and the male’s right there, it’s more a matter of logic and convenience than anything else.

It is difficult to find an ‘exact’ reason for this peculiar behavior (I suppose the Black widow doesn’t kiss and tell, hehe?) but there are some possible assumptions.

One is that the male widow at times offers itself up as prey after mating to help nourish the female to help with recently consummated egg’s production, for healthier, stronger baby spiders.

There are cases of the male widow wrapping the female in silk to prevent her from easily attacking him after mating. There appears to be some male widows that ‘offer’ themselves, and some that prefer to make a get-away. Peculiar ritual for an appropriately named spider.